Therapeutic effect of quercetin in collagen-induced arthritis

Ultrafast Interfacial Self-Assembly toward Bioderived Polyester COF Membranes with Microstructure Optimization

The precise manipulation of the microstructure (pore size, free volume distribution, and connectivity of the free-volume elements), thickness, and mechanical characteristics of membranes holds paramount significance in facilitating the effective utilization of self-standing membranes. In this contribution, the synthesis of two innovative ester-linked covalent-organic framework (COF) membranes is first reported, which are generated through the selection of plant-derived ellagic acid and quercetin phenolic monomers in conjunction with terephthaloyl chloride as a building block. The optimization of the microstructure of these two COF membranes is systematically achieved through the application of three different interfacial electric field systems: electric neutrality, positive electricity, and negative electricity. It is observed that the positively charged system facilitates a record increase in the rate of membrane formation, resulting in a denser membrane with a uniform pore size and enhanced flexibility. In addition, a correlation is identified wherein an increase in the alkyl chain length of the surfactants leads to a more uniform pore size and a decrease in the molecular weight cutoff of the COF membrane. The resulting COF membrane exhibits an unprecedented combination of high water permeance, superior sieving capability, robust mechanical strength, chemical robustness for promising membrane-based separation science and technology.

Celastrol Regulates the Hsp90-NLRP3 Interaction to Alleviate Rheumatoid Arthritis

Previous studies have verified that celastrol (Cel) protects against rheumatoid arthritis (RA) by inhibiting the NLRP3 inflammasome signaling pathway, but the molecular mechanism by which Cel regulates NLRP3 has not been clarified. This study explored the specific mechanisms of Cel in vitro and in vivo. A type II collagen-induced arthritis (CIA) mouse model was used to study the antiarthritic activity of Cel; analysis of paw swelling, determination of the arthritis score, and pathological examinations were performed. The antiproliferative and antimigratory effects of Cel on TNF-α induced fibroblast-like synoviocytes (FLSs) were tested. Proinflammatory factors were evaluated using enzyme-linked immunosorbent assay (ELISA). The expression of NF-κB/NLRP3 pathway components was determined by western blotting and immunofluorescence staining in vitro and in vivo. The putative binding sites between Cel and Hsp90 were predicted through molecular docking, and the binding interactions were determined using the Octet RED96 system and coimmunoprecipitation. Cel decreased arthritis severity and reduced TNF-α-induced FLSs migration and proliferation. Additionally, Cel inhibited NF-κB/NLRP3 signaling pathway activation, reactive oxygen species (ROS) production, and proinflammatory cytokine secretion. Furthermore, Cel interacted directly with Hsp90 and blocked the interaction between Hsp90 and NLRP3 in FLSs. Our findings revealed that Cel regulates NLRP3 inflammasome signaling pathways both in vivo and in vitro. These effects are induced through FLSs inhibition of the proliferation and migration by blocking the interaction between Hsp90 and NLRP3.

Pathophysiology, diagnosis, and herbal medicine-based therapeutic implication of rheumatoid arthritis: an overview

Rheumatoid arthritis (RA) stands as an autoimmune disorder characterized by chronic joint inflammation, resulting in profound physiological alterations within the body. Affecting approximately 0.4-1.3% of the global population, this condition poses significant challenges as current therapeutic approaches primarily offer symptomatic relief, with the prospect of complete recovery remaining elusive. This review delves into the contemporary advancements in understanding the pathophysiology, diagnosis, and the therapeutic potential of herbal medicine in managing RA. Notably, early diagnosis during the initial stages emerges as the pivotal determinant for successful recovery post-treatment. Utilizing tools such as Magnetic Resonance Imaging (MRI), anti-citrullinated peptide antibody markers, and radiography proves crucial in pinpointing the diagnosis of RA with precision. Unveiling the intricate pathophysiological mechanisms of RA has paved the way for innovative therapeutic interventions, incorporating plant extracts and isolated phytoconstituents. In the realm of pharmacological therapy for RA, specific disease-modifying antirheumatic drugs have showcased commendable efficacy. However, this conventional approach is not without its drawbacks, as it is often associated with various side effects. The integration of methodological strategies, encompassing both pharmacological and plant-based herbal therapies, presents a promising avenue for achieving substantive recovery. This integrated approach not only addresses the symptoms but also strives to tackle the underlying causes of RA, fostering a more comprehensive and sustainable path towards healing.

Rheumatoid arthritis molecular targets and their importance to flavonoid-based therapy

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.

Role of Bioactive Compounds, Novel Drug Delivery Systems, and Polyherbal Formulations in the Management of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is an autoimmune disorder that generally causes joint synovial inflammation as well as gradual cartilage and degenerative changes, resulting in progressive immobility. Cartilage destruction induces synovial inflammation, including synovial cell hyperplasia, increased synovial fluid, and synovial pane development. This phenomenon causes articular cartilage damage and joint alkalosis. Traditional medicinal system exerts their effect through several cellular mechanisms, including inhibition of inflammatory mediators, oxidative stress suppression, cartilage degradation inhibition, increasing antioxidants and decreasing rheumatic biomarkers. The medicinal plants have yielded a variety of active constituents from various chemical categories, including alkaloids, triterpenoids, steroids, glycosides, volatile oils, flavonoids, lignans, coumarins, terpenes, sesquiterpene lactones, anthocyanins, and anthraquinones. This review sheds light on the utilization of medicinal plants in the treatment of RA. It explains various phytoconstituents present in medicinal plants and their mechanism of action against RA. It also briefs about the uses of polyherbal formulations (PHF), which are currently in the market and the toxicity associated with the use of medicinal plants and PHF, along with the limitations and research gaps in the field of PHF. This review paper is an attempt to understand various mechanistic approaches employed by several medicinal plants, their possible drug delivery systems and synergistic effects for curing RA with minimum side effects.

Research progress in arthritis treatment with the active components of Herba siegesbeckiae

Arthritis is a group of diseases characterized by joint pain, swelling, stiffness, and limited movement. Osteoarthritis, rheumatoid arthritis, and gouty arthritis are the most common types of arthritis. Arthritis severely affects the quality of life of patients and imposes a heavy financial and medical burden on their families and society at large. As a widely used traditional Chinese medicine, Herba siegesbeckiae has many pharmacological effects such as anti-inflammatory and analgesic, anti-ischemic injury, cardiovascular protection, and hypoglycemic. In addition, it has significant therapeutic effects on arthritis. The rich chemical compositions of H. siegesbeckiae primarily include diterpenoids, sesquiterpenoids, and flavonoids. As one of the main active components of H. siegesbeckiae, kirenol and quercetin play a vital role in reducing arthritis symptoms. In the present study, the research progress in arthritis treatment with the active components of H. siegesbeckiae is reviewed.

Mechanistic prospective and pharmacological attributes of quercetin in attenuation of different types of arthritis

Arthritis is a frequent autoimmune disease with undefined etiology and pathogenesis. Scientific community constantly fascinating quercetin (QUR), as it is the best-known flavonoid among others for curative and preventive properties against a wide range of diseases. Due to its multifaceted activities, the implementation of QUR against various types of arthritis namely, rheumatoid arthritis (RA), osteoarthritis (OA), gouty arthritis (GA) and psoriotic arthritis (PsA) has greatly increased in recent years. Many research evidenced that QUR regulates a wide range of pathways for instance NF-κB, MAK, Wnt/β-catenine, Notch, etc., that are majorly associated with the inflammatory mechanisms. Besides, the bioavailability of QUR is a major constrain to its therapeutic potential, and drug delivery techniques have experienced significant development to overcome the problem of its limited application. Hence, this review compiled the cutting-edge experiments on versatile effects of QUR on inflammatory diseases like RA, OA, GA and PsA, sources and bioavailability, therapeutic challenges, pharmacokinetics, clinical studies as well as toxicological impacts. The use of QUR in a health context would offer a tearing and potential therapeutic method, supporting the advancement of public health, particularly, of arthritic patients worldwide.

Unveiling Neuroprotective Potential of Spice Plant-Derived Compounds against Alzheimer's Disease: Insights from Computational Studies

Alzheimer's disease (AD) is a serious threat to the global health care system and is brought on by a series of factors that cause neuronal dysfunction and impairment in memory and cognitive decline. This study investigated the therapeutic potential of phytochemicals that belong to the ten regularly used spice plants, based on their binding affinity with AD-associated proteins. Comprehensive docking studies were performed using AutoDock Vina in PyRx followed by molecular dynamic (MD) simulations using AMBER 14. The docking study of the chosen molecules revealed the binding energies of their interactions with the target proteins, while MD simulations were carried out to verify the steadiness of bound complexes. Through the Lipinski filter and admetSAR analysis, the chosen compounds' pharmacokinetic characteristics and drug likeness were also examined. The pharmacophore mapping study was also done and analyzed for best selected molecules. Additionally, principal component analysis (PCA) was used to examine how the general motion of the protein changed. The results showed quercetin and myricetin to be potential inhibitors of AChE and alpha-amyrin and beta-chlorogenin to be potential inhibitors of BuChE, exhibiting best binding energies comparable to those of donepezil, used as a positive control. The multiple descriptors from the simulation study, root mean square deviation (RMSD), root mean square fluctuation (RMSF), hydrogen bond, radius of gyration (Rg), and solvent-accessible surface areas (SASA), confirm the stable nature of the protein-ligand complexes. Molecular mechanic Poisson-Boltzmann surface area (MM-PBSA) binding free energy calculations indicated the energetically favorable binding of the ligands to the protein. Finally, according to pharmacokinetic properties and drug likeness, characteristics showed that quercetin and myricetin for AChE and alpha-amyrin and beta-chlorogenin for BuChE were found to be the most effective agents for treating the AD.

Mechanism of action of quercetin in rheumatoid arthritis models: meta-analysis and systematic review of animal studies

Quercetin, a typical flavonoid derived from a common natural plant, has multiple biological activities. Previous research in animal models has demonstrated the effectiveness of quercetin in treating rheumatoid arthritis (RA). The pharmacological effects and probable mechanisms of quercetin were evaluated in this study. Three databases, PubMed, Web of Science, and Embase, were searched for relevant studies from the creation of the databases to November 2022. Methodological quality was assessed using the SYRCLE risk of bias tool. STATA 15.1 was used to perform the statistical analysis. This research included 17 studies involving 251 animals. The results indicated that quercetin was able to reduce arthritis scores, paw swelling, histopathological scores, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-17 (IL-17), tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1), C-reactive protein (CRP), malondialdehyde (MDA), reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), nuclear factor kappa B (NF-kB) and increase interleukin-10 (IL-10), catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glutathione (GSH), and heme oxygenase-1 (HO-1). These may be related to quercetin's potential anti-inflammatory, anti-oxidative stress, and osteoprotective properties. However, more high-quality animal studies are needed to assess the effect of quercetin on RA. Additionally, the safety of quercetin requires further confirmation. Given the importance of the active ingredient, dose selection and the improvement of quercetin's bioavailability remain to be explored.

Metabolomic analysis and antibacterial and antioxidant activities of three species of Artemisia plants in Tibet

BACKGROUND

Artemisia is important medicinal plants in China and are widely used in medicine, agriculture, and food. Pharmacologically active components of the plants remain to be investigated.

METHODS

This study sought to identify and compare the chemical constituents of three species of Artemisia in Tibet using a widely-targeted metabolomics approach and their antibacterial and antioxidant capacities were determined.

RESULT

A total of 1109 metabolites within 10 categories were detected from the three species of Artemisia, including lipids, amino acids, nucleotides, flavonoids, terpenes, coumarins, organic acids, and phenolic acids. 732 different metabolites have been identified between Artemisia sieversiana and Artemisia annua, 751 different metabolites were identified between Artemisia wellbyi and A. sieversiana, and 768 differential metabolites were differentially detected from A. wellbyi and A. annua. Differentially identified compounds included flavonoids, phenolic acids, artemisinins and coumarin. A. annua contained the highest relative content of artemisinin among three Artemisia. The antimicrobial experiments showed that the three Artemisia species had strong antibiotic activities against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Proteus mirabilis and Pseudomonas aeruginosa. The biochemical analysis showed that the three species of Artemisia have strong antioxidant capacity.

CONCLUSIONS

This is the first reported attempt to comparatively determine the types of the metabolites of the three widely distributed Artemisia species in Tibet. The information should help medicinal research and facilitate comprehensive development and utilization of Artemisia species in Tibet.

Muscadine Grape (Vitis rotundifolia) and Wine Polyphenols Alleviated Arthritis and Restored the Gut Microbial Composition in Mice

This study aimed to investigate the effect of muscadine grape polyphenols (MGP) and muscadine wine polyphenols (MWP) on the onset and progression of arthritis in mice. Arthritis in male DBA/1J mice was induced by two intradermal injections of type II collagen. MGP or MWP (400 mg/kg) were orally gavaged to mice. MGP and MWP were found to delay the onset and reduce the severity and clinical symptoms of collagen induced arthritis (CIA) (p≤0.05). In addition, MGP and MWP significantly reduced the plasma concentration of TNF-α, IL-6, anti-collagen antibodies, and matrix metalloproteinase-3 in CIA mice. Based on nano CT and histological analysis, MGP and MWP reduced pannus formation, cartilage destruction, and bone erosion in CIA mice. Analysis of 16S ribosomal RNA revealed that arthritis in mice is associated with gut dysbiosis. MWP was more effective than MGP at alleviating such dysbiosis by shifting the microbiome composition towards the direction of healthy mice. Relative abundance of several genera of gut microbiome correlated with plasma inflammatory biomarkers and bone histology scores, suggesting they play a role in the development and progression of arthritis. This study suggests that muscadine grape or wine polyphenols can be used as a diet-based strategy to prevent and manage arthritis in humans.

Rat resistance to rheumatoid arthritis induction as a function of the early-phase adrenal-pineal crosstalk

Chronic inflammatory diseases are triggered by causal stimuli that might occur long before the appearance of the symptoms. Increasing evidence suggests that these stimuli are necessary but not always sufficient to induce the diseases. The murine model of type II collagen emulsified in Freund's incomplete adjuvant (collagen-induced arthritis) to induce rheumatoid arthritis (RA) follows this pattern as some animals do not develop the chronically inflamed phenotype. Considering that in the immune-pineal axis (IPA) theory adrenal-pineal cross-talk adjusts early phases of inflammatory processes, we investigated whether differences in IPA activation could explain why some animals are resistant (RES) while others develop RA. We observed a similar increase in 6-sulfatoxymelatonin (aMT6s) excretion from day 3 to 13 in both RES and RA animals, followed by a significant decrease in RA animals. This pattern of aMT6s excretion positively correlated with plasma corticosterone (CORT) in RES animals. Additionally, RA animals presented a lower aMT6s/CORT ratio than saline-injected or RES animals. Plasmatic levels of tumour necrosis factor were similar in both groups, but interleukin (IL)-1β and monocyte chemotactic protein 1 (MCP-1) levels were lower in RES compared to RA animals. IL-2 and IL-4 were decreased in RES animals compared to saline-injected animals. The aMT6s/CORT ratio inversely correlated with the paw thickness and the inflammatory score (levels of IL-1β, MCP-1, IL-2 and IL-4 combined). Thus, adrenocortical-pineal positive interaction is an early defence mechanism for avoiding inflammatory chronification. KEY POINTS: Immune-pineal axis imbalance is observed in early-phase rheumatoid arthritis development. Only resistant animals present a positive association between adrenal and pineal hormones. The 6-sulfatoxymelatonin/corticosterone ratio is decreased in animals that develop rheumatoid arthritis. The inflammatory score combining the levels of nocturnal interleukin (IL)-1β, monocyte chemotactic protein 1, IL-2 and IL-4 presents a very strong positive correlation with the size of inflammatory lesion. The 6-sulfatoxymelatonin/corticosterone ratio presents a strong negative correlation with the inflammatory score and paw oedema size.

Treg-targeted efficient-inducible platform for collagen-induced arthritis treatment

Regulatory T cells (Tregs) display great promise in rheumatoid arthritis (RA) therapy. However, their low number and differentiation rate limit their further application in the clinics. In the present study, we first optimized a combination of IL-2, TGF-β and cyclin dependent kinase inhibitor AS2863619 (IL-2/TGF-β/AS), which could induce Tregs with high efficiency in vitro. After the induced Tregs (iTregs) were confirmed to suppress lymphocyte proliferation and pro-inflammatory T help cells (Th1 and Th17) activation, a chitosan-stabilized nanoparticle drug delivery system (NDDS) was developed according to the optimized formula of IL-2/TGF-β/AS. In vivo study, the NDDS was injected into the knees of mice with collagen-induced arthritis (CIA). As a result, the NDDS remarkably reduced the pathological score of the CIA, alleviated the inflammatory cell infiltration and synovial hyperplasia, and minimized cartilage tissue damage in the knee joint of the CIA mice. Mechanically, the NDDS administration promoted Treg differentiation and decreased Th17 production, consequently reversing the ratio of Treg/Th17, and reducing the secretion of TNF-α in the sera, which facilitated to relieve the severity and progression of arthritis. In sum, NDDS capable of efficiently inducing Tregs were constructed successfully and provided a potential platform for treating RA by restoring the equilibrium of Treg/Th17 destroyed in RA.

Efficacy and safety of dietary polyphenols in rheumatoid arthritis: A systematic review and meta-analysis of 47 randomized controlled trials

OBJECTIVE

To evaluate safety and efficacy of dietary polyphenols in the treatment of rheumatoid arthritis (RA).

METHODS

CNKI, Pubmed, Cochrane library, Embase were searched to collect randomized controlled trials (RCTs) of dietary polyphenols in the treatment of RA. The databases were searched from the time of their establishment to November 8nd, 2022. After 2 reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies, Meta-analysis was performed using RevMan5.4 software.

RESULTS

A total of 49 records (47 RCTs) were finally included, involving 3852 participants and 15 types of dietary polyphenols (Cinnamon extract, Cranberry extract, Crocus sativus L. extract, Curcumin, Garlic extract, Ginger extract, Hesperidin, Olive oil, Pomegranate extract, Puerarin, Quercetin, Resveratrol, Sesamin, Tea polyphenols, Total glucosides of paeony). Pomegranate extract, Resveratrol, Garlic extract, Puerarin, Hesperidin, Ginger extract, Cinnamon extract, Sesamin only involve in 1 RCT. Cranberry extract, Crocus sativus L. extract, Olive oil, Quercetin, Tea polyphenols involve in 2 RCTs. Total glucosides of paeony and Curcumin involve in more than 3 RCTs. These RCTs showed that these dietary polyphenols could improve disease activity score for 28 joints (DAS28), inflammation levels or oxidative stress levels in RA. The addition of dietary polyphenols did not increase adverse events.

CONCLUSION

Dietary polyphenols may improve DAS28, reduce C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and improve oxidative stress, etc. However, more RCTs are needed to verify or modify the efficacy and safety of dietary polyphenols.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42022315645.

Nutrients and rheumatoid arthritis: From the perspective of neutrophils

Neutrophils are considered as core immune cells involve in the early stage of rheumatoid arthritis (RA) and participate in the disease progression. The underlining mechanisms include the elevated chemotaxis and infiltration of neutrophils, the increase in the reactive oxygen species and the promotion of neutrophil extracellular traps formation. Accumulating studies demonstrated the important role of nutrients intake played in the initiation and progression of RA. This study summarized the effects of several macronutrients and micronutrients on regulating RA through the modulation of activated neutrophils and appealed for a healthy diet in RA-risk individuals as well as RA patients.

Epimedii Herba: An ancient Chinese herbal medicine in the prevention and treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, progressive inflammatory and systemic autoimmune disease resulting in severe joint destruction, lifelong suffering and considerable disability. Diverse prescriptions of traditional Chinese medicine (TCM) containing Epimedii Herba (EH) achieve greatly curative effects against RA. The present review aims to systemically summarize the therapeutic effect, pharmacological mechanism, bioavailability and safety assessment of EH to provide a novel insight for subsequent studies. The search terms included were "Epimedii Herba", "yinyanghuo", "arthritis, rheumatoid" and "Rheumatoid Arthritis", and relevant literatures were collected on the database such as Google Scholar, Pubmed, Web of Science and CNKI. In this review, 15 compounds from EH for the treatment of RA were summarized from the aspects of anti-inflammatory, immunoregulatory, cartilage and bone protective, antiangiogenic and antioxidant activities. Although EH has been frequently used to treat RA in clinical practice, studies on mechanisms of these activities are still scarce. Various compounds of EH have the multifunctional traits in the treatment of RA, so EH may be a great complementary medicine option and it is necessary to pay more attention to further research and development.

Celastrol inhibits rheumatoid arthritis by inducing autophagy via inhibition of the PI3K/AKT/mTOR signaling pathway

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder of the synovial joints. Celastrol (Cel) is a quinone-methylated triterpenoid extracted from Tripterygium wilfordii Hook F (TwHF) that has been proven to be effective in treating RA. However, the underlying molecular mechanism of celastrol in the treatment of RA remains unknown. This study explored the protective effect of celastrol against RA and the specific mechanisms of celastrol in vitro and in vivo.

METHODS

A chicken type II collagen (CII)-induced arthritis (CIA) mouse model was used to explore the anti-arthritic effects of celastrol, and paw swelling degree, the poly-arthritis index score and serum cytokine levels were determined. Pathological morphology was observed using hematoxylin and eosin (H&E) staining. The influences of celastrol on the proliferation of tumor necrosis factor-α (TNF-α)-induced fibroblast-like synoviocytes (FLSs) were tested by Cell Counting Kit-8 (CCK-8) assays and5-ethynyl-2'-deoxyuridine (EdU) staining assays. The level of autophagy was detected by transmission electron microscopy (TEM). Furthermore, the PI3K/AKT/mTOR pathway and the status of autophagy in the CIA model and FLSs were also detected by western blot and immunofluorescence staining.

RESULTS

The results showed that celastrol decreased arthritis severity and inhibited TNF-α-induced FLSs proliferation. Additionally, celastrol decreased the secretion of pro-inflammatory cytokines. Moreover, celastrol increased autophagosome levels and LC3B protein expression in TNF-α-treated FLSs. Furthermore, celastrol increased the protein expression of LC3-II and Beclin-1 and decreased the phosphorylation degree of mTOR and AKT.

CONCLUSION

In conclusion, our findings confirmed that celastrol ameliorates RA via the up-regulation of autophagy by inhibiting the PI3K/AKT/mTOR axis.

The genus Porana (Convolvulaceae) - A phytochemical and pharmacological review

There are about 20 species of Porana Burm. f. worldwide in tropical and subtropical Asia, Africa and neighboring islands, Oceania, and the Americas. In China, India, and other places, this genus enjoys a wealth of experience in folk applications. Nevertheless, the chemical composition of only five species has been reported, and 59 compounds have been isolated and identified, including steroids, coumarins, flavonoids, quinic acid derivatives, and amides. Pharmacological studies revealed that extracts from this genus and their bioactive components exhibit anti-inflammatory, analgesic, antioxidant, anti-gout, anti-cancer, and anti-diabetic effects. Although this genus is abundant, the development of its pharmacological applications remains limited. This review will systematically summarize the traditional and current uses, chemical compositions, and pharmacological activities of various Porana species. Network analysis was introduced to compare and confirm its output with current research progress to explore the potential targets and pathways of chemical components in this genus. We hope to increase understanding of this genus’s medicinal value and suggest directions for rational medicinal development.

The mechanism of the anti-inflammatory effect of Oldenlandia diffusa on arthritis model rats: a quantitative proteomic and network pharmacologic study

BACKGROUND

In China, Oldenlandia diffusa (OD) has been prescribed as a therapeutic herb for rheumatoid arthritis (RA). We previously conducted a preliminary study of the anti-inflammatory effect of OD, and the purpose of this study is to further investigate its mechanism.

METHODS

We performed a quantitative proteomic analysis of synovium, identified the differentially expressed proteins, and performed bioinformatics analyses. With the help of network pharmacology, we aimed to find the key synovial proteins which OD or its key compound might influence. To verify the result, liquid chromatography-mass spectrometry (LC-MS) was applied to quantify and qualify the absorbable potential compounds of OD. The anti-inflammatory effect was evaluated by morphological, histopathological, and cytokine analyses. Target proteins were observed by immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

MMP3 and CAV1 were identified as 2 of the differentially expressed proteins in RA synovium, and might be influenced by quercetin, the active compound of OD. MMP3 might be altered through atherosclerosis signaling, while CAV1 might be altered through caveolar-mediated endocytosis signaling. According to our verification, quercetin was identified as the absorbed and effective compound of OD, and it could exert an anti-inflammatory effect on the collagen-induced arthritis (CIA) model, including serum cytokine expression, synovial hyperplasia and lymphocyte infiltration, articular cartilage lesion. Quercetin could also down-regulate the synovial expression of MMP3 and CAV1, and could exert better effects at a high dose.

CONCLUSIONS

Quercetin was the main active compound of OD in the treatment of RA. OD might alleviate inflammatory responses in CIA rats by suppressing the expression of MMP3 and CAV1 through quercetin, and at a high dose, quercetin could exert a better anti-inflammatory effect.

Integrated Experimental Approach, Phytochemistry, and Network Pharmacology to Explore the Potential Mechanisms of Cinnamomi Ramulus for Rheumatoid Arthritis

Cinnamomi Ramulus (CR) has been extensively used as a remedy for inflammatory diseases in China. This study adopted an integrative approach of experimental research, phytochemistry, and network pharmacology to investigate its alleviative effects on rheumatoid arthritis (RA) and the underlying potential mechanisms. CR extract (50, 100, and 200 mg/kg) and methotrexate (MTX) significantly ameliorated RA symptoms in the collagen-induced arthritis (CIA) rat model. They also reduced paw volume, arthritis index, proinflammatory cytokines (TNF-α, IL-17A, IL-6, and IL-1β), and oxidative damage. Sixty-three compounds were systematically identified as the basic components of CR. Fifty-five common genes obtained from compounds and GEO databases were employed to construct the protein-protein interaction (PPI) network. Among them, 20 hub genes were identified via the cytoHubba. Enrichment analysis of the common genes indicated that the TNF signaling pathway and IL-17 signaling pathway might be the potential key pathways. Moreover, molecular docking methods confirmed the high affinity between the top 10 bioactive components of CR and the top 10 targets. In addition, in vitro results showed that CR extract (0.2, 0.4, and 0.8 mg/mL) inhibited inflammation and oxidative damage in MH7A cells stimulated by lipopolysaccharide (LPS). In summary, this study adopted multiple approaches to elucidate the protective effect and potential mechanisms of CR on RA, indicating that CR might be a promising herbal candidate for further investigation of RA treatment.

Inflammatory Cytokine-Neutralizing Antibody Treatment Prevented Increases in Follicular Helper T Cells and Follicular Regulatory T Cells in a Mouse Model of Arthritis

Background

Follicular T helper (TFH) and follicular regulatory T (TFR) cells play important roles in humoral immunity. Nevertheless, their significance in rheumatoid arthritis (RA) pathogenesis has not been fully elucidated. As an important treatment strategy, the effect of inflammatory factor-neutralizing antibodies on TFH and TFR in RA remains unclear.

Methods

We used the collagen-induced arthritis (CIA) mouse model to illustrate the quantity and functional changes in TFH and TFR cells. The changes of plasmablast, TFH and TFR cells in the spleen and peripheral blood of CIA mice were analyzed by flow cytometry. The levels of TFH and TFR and their functional subsets in the spleen after anti-inflammatory antibody treatment were analyzed and compared. The functional changes of TFH and TFR in CIA mice before and after treatment were detected by in vitro culture experiments.

Results

Plasmablast levels were increased in CIA spleen and peripheral blood and both TFH and TFR cell levels were upregulated. TFH and TFR cells were decreased significantly after the anti-inflammatory antibody treatment. TIGIT⁺ and TIGIT⁺CD226⁻ TFH cells in CIA mouse spleen were elevated and PD-1 and ICOS expression on spleen TFH and TFR cells was increased. Both the ability of TFH cells to secrete IL-21 and aid B cells and the ability of TFR cells to secrete IL-10 and inhibit TFH cells were enhanced in the CIA mice. After antibody treatment, the cell subsets and functions were recovered.

Conclusion

Germinal center TFH and TFR cells were increased and their functions were enhanced. With inflammatory factor-neutralizing antibody treatment, TFH and TFR subsets and their functions returned to normal. These findings provide important information on the dynamics of humoral immune-related cell subsets in RA and the effects of treatment on them.

Pharmacological Aspects of Natural Quercetin in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can lead to severe joint damage, disability and mortality. Quercetin (QUE) is a natural flavonoid that is ubiquitous in fruits and vegetables. This article reviews the effect of QUE on articular and extra-articular manifestations of RA in vitro and in vivo. In general, for articular manifestations, QUE inhibited synovial membrane inflammation by reducing inflammatory cytokines and mediators, decreasing oxidative stress, inhibiting proliferation, migration and invasion, and promoting apoptosis of fibroblast-like synoviocytes (FLS), regulated autoimmune response through modulating Th17/Treg imbalance and Th17 cells differentiation, reducing autoantibodies levels and regulating ectonucleoside triphosphate diphosphohydrolase (E-NTPDase)/ectoadenosine deaminase (E-ADA) activities, reduced bony damage via lowering matrix metalloproteinase (MMP)-1, MMP-3, receptor activator of nuclear factor kappa B ligand (RANKL) expression and osteoclasts formation. For extra-articular manifestations, QUE could reverse the neurodegenerative processes of the enteric nervous system (ENS) and exhibited cytoprotective, genoprotective and hepatoprotective effects. In addition, we also summarize some contradictory experimental results and explore the possibility for these differences to form a sound basis for the clinical application of QUE for RA.

Anti-rheumatic, and analgesic effects by the parent tuberous roots of Aconitum jaluense in adjuvant induced arthritis rats

AIM OF THE STUDY

The aim of this study was to test the anti-rheumatic effects of A. jaluense tubers in acute and chronic arthritis rats, and to assign its ingredients through UHPLC-TOF/MS.

MATERIALS AND METHODS

Subcutaneous injection of carrageenan for acute arthritis and complete Freund's adjuvant (CFA) for chronic arthritis was carried out in the hind paw of SD rats. The paw volume was measured by a plethysmometer thermal hyperalgesia was tested using a thermal plantar tester, and mechanical hyperalgesia was evaluated by ankle flexion evoked vocalizations. The expression of c-Fos in the brain hippocampus was measured with the avidin-biotin-peroxidase technique. The ingredients were assigned by UHPLC-TOF/MS, chromatography was performed by UHPLC system with DAD detector and BEH C₁₈ column, and spectroscopy was conducted by ESI-MS system.

RESULTS AND DISCUSSION

The 80% ethanoic extract of A. jaluense tubers showed an acute anti-inflammatory effect by suppressing the edema volume in the hind paw of carrageenan-stimulated rats. In addition, A. jaluense tubers exerted an anti-rheumatic activity by reducing the secondary swelling volume from an immunological reaction in the left hind paw of CFA-induced chronic arthritis rats. Additionally, oral treatment with the 80% ethanoic extract -showed potent analgesic effects in the arthritis rats by recovering the paw withdrawal latency stimulated by the thermal hyperalgesia and by reducing the vocalization scores evoked by ankle flexion on both hind paws. Moreover, its treatment also indicated an anti-psychiatric effect by controlling the c-Fos protein expression of the brain hippocampus in CFA-stimulated arthritis rats. These results suggested that these therapeutic effects were exhibited by less toxic mono-esterified diterpenoid alkaloids (MDAs), and nontoxic non-esterified diterpenoid alkaloids (NDAs).

CONCLUSION

A. jaluense tubers may act as viable therapeutic or preventive candidates for acute and chronic arthritis, particularly, for immune-inflammatory rheumatoid arthritis to suppress the pain and psychiatric condition.

High-Throughput Chinmedomics Strategy Discovers the Quality Markers and Mechanisms of Wutou Decoction Therapeutic for Rheumatoid Arthritis

Wutou decoction (WTD) is a traditional Chinese medicine prescription for the treatment of rheumatoid arthritis (RA), and this study systematically analyzed the metabolic mechanism and key pharmacodynamic components of WTD in RA rats by combining untargeted metabolomics and serum pharmacochemistry of traditional Chinese medicine to enrich the evidence of WTD quality markers (Q-markers) studies. WTD prevented synovial edema in RA rats and reduced tumor necrosis factor-alpha and interleukin 6 levels in rat serum, according to the results of an enzyme-linked immunosorbent examination and histopathological inspection. In model rats, pattern recognition and multivariate statistical analysis revealed 24 aberrant metabolites that disrupted linoleic acid metabolism, arachidonic acid metabolism, arginine and proline metabolism, etc. However, continued dosing of WTD for 28 days reversed 13 abnormal metabolites, which may be an important therapeutic mechanism from a metabolomic perspective. Importantly, 12 prototypical components and 16 metabolites from WTD were characterized in RA rat serum. The results of Pearson correlation analysis showed that aconitine, L-ephedrine, L-methylephedrine, quercetin, albiflorin, paeoniflorigenone, astragaline A, astragaloside II, glycyrrhetic acid, glycyrrhizic acid, licurazide, and isoliquiritigenin are the key pharmacological components that regulate the metabolism of RA rats, and they are identified as Q-markers. In sum, utilizing metabolomics and serum pharmacochemistry of traditional Chinese medicine, the metabolic mechanisms and Q-markers of WTD therapy in RA rats were revealed, providing a theoretical basis for the quality control investigation of WTD.

Drug Candidates for Autoimmune Diseases

Most of the immunosuppressive drugs used in the clinic to prevent organ rejection or to treat autoimmune disorders were originally isolated from fungi or bacteria. Therefore, in addition to plants, these are valuable sources for identification of new potent drugs. Many side effects of established drugs limit their usage and make the identification of new immunosuppressants necessary. In this review, we present a comprehensive overview of natural products with potent anti-inflammatory activities that have been tested successfully in different models of chronic inflammatory autoimmune diseases. Some of these candidates already have passed first clinical trials. The anti-inflammatory potency of these natural products was often comparable to those of established drugs, and they could be used at least in addition to standard therapy to reduce their dose to minimize unwanted side effects. A frequent mode of action is the inhibition of classical inflammatory signaling pathways, such as NF-κB, in combination with downregulation of oxidative stress. A drawback for the therapeutic use of those natural products is their moderate bioavailability, which can be optimized by chemical modifications and, in addition, further safety studies are necessary. Altogether, very interesting candidate compounds exist which have the potential to serve as starting points for the development of new immunosuppressive drugs.

Sarcococca saligna Hydroalcoholic Extract Ameliorates Arthritis in Complete Freund's Adjuvant-Induced Arthritic Rats via Modulation of Inflammatory Biomarkers and Suppression of Oxidative Stress Markers

Traditionally, Sarcococca saligna has been used for the treatment of arthritis and many other inflammatory disorders. The current study was planned to give scientific evidence to this traditional use of S. saligna. Phytochemical profiling of SSME was carried out by using electrospray ionization mass spectrometry (ESI-MS/MS). Complete Freund's adjuvant (CFA), 150 μL was injected in the subplantar region of the left hind paw to induce arthritis in rats. Aqueous methanolic extract of S. saligna (SSME) was administered orally at 250, 500, or 1000 mg/kg dose from the 7th day to the 28th day of the study to explore its anti-arthritic potential. Histopathological and radiographic assessment of joints and enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) analyses were performed. Determination of oxidative stress biomarkers in the serum was also carried out. ESI-MS/MS identified ten such phytoconstituents which have reported strong anti-inflammatory and anti-arthritic activity. The SSME extract considerably reduced paw inflammation and arthritic index, subdued cachexia, and significantly improved biochemical and hematological changes. Oxidative stress decreased in SSME administered rats dose-dependently. Histopathological and radiographic evaluations also showed the anti-arthritic activity of SSME, which was associated with the downregulation of tumor necrosis factor (TNF)-α, nuclear factor (NF)-kB, COX-2, interleukin (IL)-6, and IL-1β and upregulation of I-kB, IL-4, and IL-10, in contrast to disease group rats. The outcomes of the study proposed that S. saligna have anti-arthritic potential, supporting its traditional use for rheumatoid arthritis treatment.

Chaenomeles Fructus (CF), the Fruit of Chaenomeles sinensis Alleviates IL-1β Induced Cartilage Degradation in Rat Articular Chondrocytes

Osteoarthritis (OA) causes persistent pain, joint dysfunction, and physical disability. It is the most prevalent type of degenerative arthritis, affecting millions of people worldwide. OA is currently treated with a focus on pain relief, inflammation control, and artificial joint surgery. Hence, a therapeutic agent capable of preventing or delaying the progression of OA is needed. OA is strongly associated with the degeneration of the articular cartilage and changes in the ECM, which are primarily associated with a decrease in proteoglycan and collagen. In the progress of articular cartilage degradation, catabolic enzymes, such as matrix metalloproteinases (MMPs), are activated by IL-1β stimulation. Given the tight relationship between IL-1β and ECM (extra-cellular matrix) degradation, this study examined the effects of Chaenomeles Fructus (CF) on IL-1β-induced OA in rat chondrocytes. The CF treatment reduced IL-1β-induced MMP3/13 and ADAMTS-5 production at the mRNA and protein levels. Similarly, CF enhanced col2a and aggrecan accumulation and chondrocyte proliferation. CF inhibited NF-κB (nuclear factor kappa B) activation, nuclear translocation induced by IL-1β, reactive oxygen species (ROS) production, and ERK phosphorylation. CF demonstrated anti-OA and articular regeneration effects on rat chondrocytes, thus, suggesting that CF is a viable and fundamental therapeutic option for OA.

Metabolomics analysis of three Artemisia species in the Tibet autonomous region of China

BACKGROUND

The Artemisia species are widely distributed around the world, and have found important usage in traditional medicinal practice. This study was designed to investigate the metabolites of Tibetan Artemisia species and understand the metabolic pathways.

METHODS

The metabolites from three Artemisia species in Tibet, were analyzed using LC-MS/MS. The differential metabolites were classified and analyzed by principal component analysis (PCA), partial least squares analysis and hierarchical clustering. KEGG Pathway enrichment analysis was used to identify the key metabolic pathways involved in the differential metabolites of three Artemisia species.

RESULT

The metabolites of three Artemisia species were analyzed. Under the positive ion mode in LC-MS/MS, 262 distinct metabolites were differentially detected from Artemisia sieversiana and Artemisia annua, 312 differential metabolites were detected from Artemisia wellbyi and Artemisia sieversiana, 306 differential metabolites were screened from Artemisia wellbyi and Artemisia annua. With the negative ion mode, 106 differential metabolites were identified from Artemisia sieversiana and Artemisia annua, 131 differential metabolites were identified from Artemisia wellbyi and Artemisia sieversiana,133 differential metabolites were differentially detected from Artemisia wellbyi and Artemisia annua. The selected differential metabolites were mainly organic acids and their derivatives, ketones, phenols, alcohols and coumarins. Among these natural compounds, artemisinin, has the highest relative content in Artemisia annua.

CONCLUSIONS

This is the first reported attempt to comparatively determine the types of the metabolites of the three widely distributed Artemisia species in Tibet. The information should help medicinal research and facilitate comprehensive development and utilization of Artemisia species in Tibet.

Therapeutic effects of dracocephalum heterophyllum in collagen-induced arthritis

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease characterized by synovial inflammation, joint swelling, and cartilage and bone destruction. Dracocephalum heterophyllum (DH) is a compound in traditional Chinese herbal medicine well known for its anti-inflammatory, antiviral and antioxidant activities. In the present work, the therapeutic effects of DH were investigated in collagen-induced arthritis. Arthritis severity was assessed by clinical score, X-ray, and histopathological features. Expression of inflammatory cytokines was detected by qPCR and ELISA whereas anti-type II collagen antibodies were determined by ELISA. DH treatment significantly alleviated clinical scores, synovial inflammation, joint swelling, and cartilage and bone destruction. DH also reduced the production of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin-1β (IL-1β), and decreased the serum levels of anti-type II collagen specific IgG antibodies in collagen-induced arthritis. The therapeutic effects of DH in collagen-induced arthritis provide evidence that DH might be a potential therapeutic drug for rheumatoid arthritis.

Quercetin mitigates rheumatoid arthritis by inhibiting adenosine deaminase in rats

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease characterized by synovial proliferation and bone destruction. Adenosine deaminase (ADA) is a key inflammatory enzyme that increases joint stiffness and pain in RA. In this study, we evaluated the in-silico, and in vivo inhibitory effect of quercetin isolated from Egyptian Fenugreek on ADA enzyme activity. We also determined the combinatorial effect of quercetin on methotrexate mediated anti-inflammatory efficacy and toxicity. In-silico molecular docking was conducted and confirmed in an in vivo RA rat model. The results showed that the inhibition constant of quercetin on joint ADA by docking and in-vitro was 61.9 and 55.5 mM, respectively. Therefore, quercetin exhibits anti-inflammatory effect in a rat RA model as evidenced by reducing the specific activity of ADA in joint tissues, lower jaw volume, enhance body weight, downregulate ADA gene expression, reduce levels of RA cytokines interleukin-1^β, interleukin-6, tumor necrosis factor-α, also, rheumatoid factor, C-reactive protein, and anti-cyclic citrullinated peptide RA biomarker levels. These findings demonstrate that the purified quercetin has a promising anti-inflammatory effect against RA disease through its inhibitory effects on the ADA enzyme. Furthermore, isolated quercetin improved the anti-inflammatory efficacy of methotrexate, reduced its toxic effects by increasing antioxidant enzymes and reducing oxidative stress.

OX40-Fc Fusion Protein Alleviates PD-1-Fc-Aggravated Rheumatoid Arthritis by Inhibiting Inflammatory Response

BACKGROUND

Researches have confirmed that the abnormal signals of OX40 and PD-1 lead to the changes of T cell biological behavior, thus participating the immunopathological process of RA. However, the pathogenesis of RA immunopathological process has not been clarified yet.

METHODS

30 DBA/1 mice were randomly divided into 5 groups (6 mice per group): control group, collagen-induced arthritis (CIA) group, PD-1-Fc/CIA group, OX40-Fc/CIA group, and PD-1-Fc + OX40-Fc/CIA group. The pathological changes in mice joints were observed by H&E staining. The proportion of CD4+ T, CD8+ T, CD28+, and CD19+ cells in peripheral blood mononuclear cells (PBMCs) was detected by flow cytometry. Serum inflammatory factors (CRP, IL-2, IL-4, IL-1β, INF-γ) and bone metabolism-related genes (CTX-I, TRACP-5b, BALP) were detected by ELISA assay. Western blotting was applied to measure the NF-κB signaling pathway-related protein (p-IKKβ, p-IκBα, p50) expression in synovial tissue of mice joint.

RESULTS

Compared with the control group, CIA mice showed significant increases in arthritis score and pathological score. In the CIA group, a marked decrease was identified in the proportion of CD8+ T, CD19+, and CD68+ cells. Additionally, the CIA group was associated with upregulation of secretion of inflammatory factors in serum and expression of bone metabolism-related genes and NF-κB pathway-related proteins. Compared with the CIA group, the same indexes above showed a further aggravation in the PD-1-Fc group while all indexes improved in the OX40-Fc group. Besides, OX40-Fc fusion protein slowed down significantly the further deterioration of CIA mouse pathological process caused by PD-1-Fc fusion protein.

CONCLUSION

OX40-Fc fusion protein alleviates PD-1-Fc-aggravated RA by inhibiting inflammatory response. This research provides biological markers with clinical significance for diagnosis and prognosis of RA, as well as offers theoretical and experimental foundation to the new targets for immune intervention.

Elucidating the material basis and potential mechanisms of Ershiwuwei Lvxue Pill acting on rheumatoid arthritis by UPLC-Q-TOF/MS and network pharmacology

Ershiwuwei Lvxue Pill (ELP, མགྲིན་མཚལ་ཉེར་ལྔ།), a traditional Tibetan medicine preparation, has been used hundreds of years for the clinical treatment of rheumatoid arthritis (RA) in the highland region of Tibet, China. Nevertheless, its chemical composition and therapeutic mechanism are unclear. This study aimed to uncover the potentially effective components of ELP and the pharmacological mechanisms against RA by combing UPLC-Q-TOF/MS and network pharmacology. In this study, 96 compounds of ELP were identified or tentatively characterized based on UPLC-Q-TOF/MS analysis. Then, a total of 22 potential bioactive compounds were screened by TCMSP with oral bioavailability and drug-likeness. Preliminarily, 10 crucial targets may be associated with RA through protein-protein interaction network analysis. The functional enrichment analysis indicated that ELP exerted anti-RA effects probably by synergistically regulating many biological pathways, such as PI3K-Akt, Cytokine-cytokine receptor interaction, JAK-STAT, MAPK, TNF, and Toll-like receptor signaling pathway. In addition, good molecular docking scores were highlighted between five promising bioactive compounds (ellagic acid, quercetin, kaempferol, galangin, coptisine) and five core targets (PTGS2, STAT3, VEGFA, MAPK3, TNF). Overall, ELP can exert its anti-RA activity via multicomponent, multitarget, and multichannel mechanisms of action. However, further studies are needed to validate the biological processes and effect pathways of ELP.

Reveals of quercetin's therapeutic effects on oral lichen planus based on network pharmacology approach and experimental validation

Oral lichen planus (OLP) is a localized autoimmune disease of the oral mucosa, with an incidence of up to 2%. Although corticosteroids are the first-line treatment, they cause several adverse effects. Quercetin, a naturally occurring compound, has fewer side-effects and provides long-term benefits. Besides, it has powerful anti‑inflammatory activities. Here, we combined network pharmacology with experimental verification to predict and verify the key targets of quercetin against OLP. First, 66 quercetin-OLP common targets were analyzed from various databases. The protein–protein interaction (PPI) network was constructed. Topology analysis and MCODE cluster analysis of common targets were conducted to identify 12 key targets including TP53, IL-6 and IFN-γ and their connections. Gene functions and key signaling pathways, including reactive oxygen species metabolism, IL-17 pathway and AGE-RAGE pathway, were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Then, in vitro experiments showed that quercetin interfered with Th1/Th2 balance by acting on IL-6 and IFN-γ to modulate the immune system in treating OLP. Quercetin considerably affected the apoptosis and migration of T lymphocytes in OLP patients. Our study reveals the potential therapeutic targets and signaling pathways of quercetin associated with OLP, and establishes the groundwork for future clinical applications.

Na-AIP-1 secreted by human hookworms suppresses collagen-induced arthritis

Proteins from helminths have been posed as new immunomodulatory agents with exciting potential in the treatment of immune-mediated diseases including rheumatoid arthritis (RA). In this study we assess the effects of a helminthic excretory/secretory (ES) protein Na-AIP-1 as monotherapy and in combination with methotrexate (MTX) in the well-described collagen-induced arthritis (CIA) model of RA. CIA was induced in DBA/1 J mice which were treated after the onset of arthritis with Na-AIP-1 monotherapy, MTX or Na-AIP-1 + MTX. The clinical scores for weight, arthritis and paw width were recorded along with joint histology as outcome measures. For the clinical parameters of weight, paw score and paw width, none of the Na-AIP-1 monotherapy, MTX therapy or Na-AIP-1 + MTX combination therapy groups displayed any significant difference when compared to the arthritis control. However, a significant reduction in histological score was identified after both monotherapy (Na-AIP-1: 0.83 ± 0.24 vs Arthritis control: 5.58 ± 1.49, p = 0.0277) and combination therapy (Na-AIP-1 + MTX: 0.55 ± 0.28 vs Arthritis control: 5.58 ± 1.49, p = 0.0233) when compared to arthritis control. Furthermore, Na-AIP-1 as both monotherapy (Na-AIP-1: 0.83 ± 0.24 vs MTX: 5.73 ± 1.82 p = 0.0261) and combination therapy (Na-AIP-1 + MTX: 0.55 ± 0.28 vs MTX: 5.73 ± 1.82, p = 0.0221) also significantly reduced histological score when compared to MTX monotherapy. Na-AIP-1 significantly reduced joint pathology in CIA. The hookworm protein Na-AIP-1 seems to be effective in the treatment of RA as monotherapy and when dosed together with MTX, constituting a potential new candidate for drug development. Research should focus on elucidating the mechanism of Na-AIP-1 action as a means to identify novel targets for therapeutics and to further our current understanding of immunobiology in RA.

The role of flavonoids in inhibiting IL-6 and inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. RA has well-known clinical manifestations and can cause progressive disability and premature death along with socioeconomic burdens. Interleukin-6 (IL-6) has been implicated in the pathology of RA where it can stimulate pannus formation, osteoclastogenesis, and oxidative stress. Flavonoids are plant metabolites with beneficial pharmacological effects, including anti-inflammatory, antioxidant, antidiabetic, anticancer, and others. Flavonoids are polyphenolic compounds found in a variety of plants, vegetables, and fruits. Many flavonoids have demonstrated anti-arthritic activity mediated mainly through the suppression of pro-inflammatory cytokines. This review thoroughly discusses the accumulate data on the role of flavonoids on IL-6 in RA.

Herbal Formula Longteng Decoction Promotes the Regression of Synovial Inflammation in Collagen-Induced Arthritis Mice by Regulating Type 2 Innate Lymphocytes

The etiology and pathogenesis of rheumatoid arthritis (RA) have not yet been fully elucidated, with greater adverse drug effects in traditional treatment of RA. It is particularly necessary to develop and study Chinese herbal formula as a supplement and alternative drug for the treatment of RA. The traditional Chinese medicine compound Longteng Decoction (LTD), as an empirical prescription in the treatment of RA in Dongzhimen Hospital of Beijing University of Chinese Medicine, has been widely used in clinic. Type 2 innate lymphocytes (ILC2s) have specific transcription factors and signature cytokines that are very similar to Th cells, which have been proved to be necessary in addressing RA inflammation, and are potential targets for RA prevention and treatment. Our previous studies have confirmed that LTD can intervene in the differentiation of peripheral blood Th17 and Treg cells, reduce joint pain index and swelling degree, shorten the time of morning stiffness, reduce ESR, and inhibit joint inflammation. However, it is unclear whether LTD can promote the regression of RA synovial inflammation by regulating the immune response mechanism of ILC2s.Therefore, our team established a collagen-induced arthritis mouse model and conducted an experimental study with LTD as the intervention object. The results showed that joint swelling, synovial inflammatory infiltration, and articular cartilage destruction were alleviated in CIA mice after intervention with LTD. The proliferation and differentiation of Th17 inflammatory cells and the secretion of proinflammatory cytokines (IL-17 and IFN-γ) were inhibited. In addition, LTD can also activate ILC2s to secrete the anti-inflammatory cytokine IL-4, activate the STAT6 signaling pathway, and act synergistic with Treg cells to inhibit the infiltration of type M1 macrophages in synovial tissue and promote its transformation to M2 phenotype. Taken together, these results confirm that LTD can be used as an adjunct or alternative to RA therapy by modulating the ILC2s immune response network and slowing down the inflammatory process of synovial tissue.

Levels of polyphenols and phenolic metabolites in breast milk and their association with plant-based food intake in Hong Kong lactating women

Dietary polyphenols are phytonutrients exhibiting multiple health benefits in humans including those in infants. However, data on breast milk (poly)phenolic composition are limited, especially among Asian populations. This study aimed to assess the levels of dietary polyphenols and their microbial-derived metabolites in the breast milk of Hong Kong lactating women, and how maternal diet correlated with the phenolic composition in breast milk. Breast milk samples from 89 healthy Hong Kong lactating women (aged 19-40 years) were collected. Maternal intake of plant-based foods and polyphenols was estimated through 3-day dietary records and the Phenol-Explorer database. Twelve commonly consumed polyphenols including their microbial-derived metabolites in breast milk were quantified using an optimized and validated UHPLC-MS/MS method. The effect of maternal intake on breast milk phenolic levels was then examined via the Pearson correlation test. The mean concentrations of individual phenolic compounds ranged from 5.1 nmol L^-1 (chlorogenic acid) to 731.5 nmol L^-1 (3,4-dihydroxybenzoic acid). Despite suboptimal intake of fruits and vegetables among our participants, breast milk phenolic levels were comparable to those of foreign populations. Significant correlations were found between dietary intake and multiple phenolics, particularly legume and daidzein (r = 0.33, P = 0.001), and tea and epicatechin (r = 0.30, P = 0.03). Regarding phenolic metabolites, 3,4-dihydroxyphenylacetic acid was significantly correlated with several polyphenols, particularly quercetin (r = 0.34, P = 0.002), and equol was exclusively correlated with daidzein (r = 0.46, P < 0.001). Our findings support that intake of plant-based foods significantly affects breast milk phenolic composition. Future investigation on the bioavailability and health outcomes in infants is warranted to substantiate the transferability of these bioactive phytonutrients from mother to child through lactation, and to promote maternal intake of polyphenol-rich foods.

Quercetin Preserves Oral Cavity Health by Mitigating Inflammation and Microbial Dysbiosis

Failure to attenuate inflammation coupled with consequent microbiota changes drives the development of bone-destructive periodontitis. Quercetin, a plant-derived polyphenolic flavonoid, has been linked with health benefits in both humans and animals. Using a systematic approach, we investigated the effect of orally delivered Quercetin on host inflammatory response, oral microbial composition and periodontal disease phenotype. In vivo, quercetin supplementation diminished gingival cytokine expression, inflammatory cell infiltrate and alveolar bone loss. Microbiome analyses revealed a healthier oral microbial composition in Quercetin-treated versus vehicle-treated group characterized by reduction in the number of pathogenic species including Enterococcus, Neisseria and Pseudomonas and increase in the number of non-pathogenic Streptococcus sp. and bacterial diversity. In vitro, Quercetin diminished inflammatory cytokine production through modulating NF-κB:A20 axis in human macrophages following challenge with oral bacteria and TLR agonists. Collectively, our findings reveal that Quercetin supplement instigates a balanced periodontal tissue homeostasis through limiting inflammation and fostering an oral cavity microenvironment conducive of symbiotic microbiota associated with health. This proof of concept study provides key evidence for translational studies to improve overall health.

Stachys schtschegleevii tea, matrix metalloproteinase, and disease severity in female rheumatoid arthritis patients: a randomized controlled clinical trial

BACKGROUND

Stachys schtschegleevii (SSC) is a herbal medicine used to treat infections. To date, this is the first study aimed to investigate the effects of SSC tea on disease activity score (DAS), serum inflammatory biomarkers and matrix metalloproteinases (MMP-1 and MMP-3) among women with rheumatoid arthritis (RA).

METHODS

This pilot, triple-blind, randomized controlled clinical trial was conducted among forty-four women (age: 30-65 years) diagnosed with moderately active RA. Subjects were randomly assigned (1:1 ratio) into either SSC group (2.4 g/day SSC + 2.4 g/day black tea, n=22) or placebo (2.4 g/day black tea, n=22) for 8 weeks. Serum high-sensitivity C-reactive protein (hs-CRP), interleukin-1 beta (IL-1β), and MMPs were measured using ELISA. According to the American College of Rheumatology guideline considering hs-CRP, DAS28 was assessed.

RESULTS

Both study groups had respondent rates above 94.9%. The SSC intervention caused significant reductions in the number and the percent changes of the tender joints (SSC: -74.39% vs. placebo: -57.15%, mean differences= -0.77; P<0.05) and DAS28 [SSC: -32.44% vs. placebo: -22.32%, mean differences= -0.41, P<0.05). Unlike the intervention within SSC group that showed significant reductions in the mean serum levels of hs-CRP, IL-1β, and MMP-3, SSC caused significant MMP-3 reductions (SSC: -20.59% vs. placebo: 1.29%, P<0.05).

CONCLUSION

The SSC intervention showed an appropriate clinical efficacy for female RA patients, accompanying remarkable reductions in the number of tender and swollen joints, DAS28, and serum levels of MMP-3. This can provide additional insights to the interventional studies controlling RA-related pathological and inflammatory outcomes. Trial registration Prospectively registered at the Iranian Registry of Clinical Trials (IRCT), linked to the WHO Registry Network ( https://en.irct.ir/trial/11602 , IRCT registration number: IRCT2015032011335N5, Registration date:2015-05-12). Key Points • Stachys schtschegleevii improved clinical outcomes and attenuated disease severity in RA patients. • Stachys schtschegleevii ameliorated serum level of MMP-3 in RA patients.

Low dose of quercetin-loaded pectin/casein microparticles reduces the oxidative stress in arthritic rats

AIMS

Quercetin has been investigated as an agent to treat rheumatoid arthritis. At high doses it improves inflammation and the antioxidant status of arthritic rats, but it also exerts mitochondriotoxic and pro-oxidant activities. Beneficial effects of quercetin have not been found at low doses because of its chemical instability and low bioavailability. In the hope of overcoming these problems this study investigated the effects of long-term administration of quercetin-loaded pectin/casein microparticles on the oxidative status of liver and brain of rats with adjuvant-induced arthritis.

MAIN METHODS

Particle morphology was viewed with transmission electron microscopy and the encapsulation efficiency was measured indirectly by X-ray diffraction. Quercetin microcapsules (10 mg/Kg) were orally administered to rats during 60 days. Inflammation indicators and oxidative stress markers were measured in addition to the respiratory activity and ROS production in isolated mitochondria.

KEY FINDINGS

Quercetin was efficiently encapsulated inside the polymeric matrix, forming a solid amorphous solution. The administration of quercetin microparticles to arthritic rats almost normalized protein carbonylation, lipid peroxidation, the levels of reactive oxygen species as well as the reduced glutathione content in both liver and brain. The paw edema in arthritic rats was not responsive, but the plasmatic activity of ALT and the mitochondrial respiration were not affected by quercetin, indicating absence of mitochondriotoxic or hepatotoxic actions.

SIGNIFICANCE

Quercetin-loaded pectin/casein microcapsules orally administered at a low dose improve oxidative stress of arthritic rats without a strong anti-inflammatory activity. This supports the long-term use of quercetin as an antioxidant agent to treat rheumatoid arthritis.

Traditional herbal medicine: Therapeutic potential in rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease influenced by diverse endogenous and exogenous factors. It is characterized by cartilage and bone destruction. The current conventional allopathic therapy is expensive and carries adverse side effects. Recently, there were some ethnopharmacological studies on RA including anti-RA effects and therapeutic targets of distinct dosage forms of traditional herbal medicines (THMs).

AIM OF THE REVIEW

This review provides a brief overview of the current understanding of the potential pharmacological mechanisms of THMs (active constituents, extracts and prescriptions) in RA. This study is intended to provide comprehensive information and reference for exploring new therapeutic strategies of THMs in the RA treatment.

MATERIALS AND METHODS

This review captured scientific literatures invivo and vitro experiments on effects of anti-RA THMs published between 2016 and 2021 from journals and electronic databases (e.g. PubMed, Elsevier, Science Direct, Web of Science and Google Scholar). Relevant literatures were searched and analyzed by using keywords such as 'rheumatoid arthritis AND traditional herbal medicines', 'rheumatoid arthritis AND immune cells', 'rheumatoid arthritis AND inflammation', 'rheumatoid arthritis AND miRNA', 'rheumatoid arthritis AND Angiogenesis', 'rheumatoid arthritis AND oxidative stress', 'rheumatoid arthritis AND osteoclasts', 'rheumatoid arthritis AND CIA model', 'rheumatoid arthritis AND AA model' AND 'rheumatoid arthritis herbal prescription'.

RESULTS

Experiments in vitro and in vivo jointly demonstrated the potential of THMs in the RA treatment. There are plentiful therapeutic targets in RA. THMs and active ingredients could alleviate RA symptoms through different therapeutic targets, such as immunoregulation, inflammation, fibroblast-like synoviocytes (FLSs), microRNAs (miRNAs), angiogenesis, oxidative stress, osteoclasts and multiple targets interaction. Anti-RA THMs, active ingredients and prescriptions through corresponding therapeutic targets were summarized and classified.

CONCLUSIONS

Flavonoids, phenolic acids, alkaloids and triterpenes of THMs are identified as the main components to ameliorate RA. Regulation of different and multiple related therapeutic targets by THMs and their active ingredients were associated with greater therapeutic benefits, among which inflammation is the main therapeutic target. Nonetheless, further studies are required to unravel the complexities and in-depth mechanisms of THMs in alleviating RA.

Styphnolobium japonicum (L.) Schott Flower Extract Alleviates Oxidative Stress and Inflammatory Factors in the Adjuvant-Induced Arthritis Rat Model

Introduction

This research was to evaluate the beneficial effects of Styphnolobium japonicum (L.) Schott flower extract (SJF) on the adjuvant-induced arthritis rat model.

Methods

Arthritis was evoked by injection of complete Freund's adjuvant (CFA) in the hind paw. SJF (150 or 300 mg/kg/day) or Celecoxib (5 mg/kg/day) were administered intragastrically from the 0th day to the 28th day. The arthritis symptoms (paw edema, arthritic scores, mechanical hyperalgesia, and thermal hyperalgesia), inflammation biomarkers (RT and CRP), related enzymes (MMP1 and MMP13), oxidative stress markers (CAT, SOD, GPx, and MDA), and inflammatory cytokines (IL-6, IFN-γ, TNF-α, and IL-1β) of SJF-treated CFA rats were evaluated.

Results

CFA rats exhibited severe arthritis symptoms, increased oxidative stress, and inflammatory cytokines. Interestingly, SJF treatment relieving arthritis symptoms and restored body weight gain compared with those in the CFA group. SJF treatment decreased the levels of CRP, RF, MMP1, and MMP13 in the CFA group. Besides, SJF treatment increased the activities of antioxidant enzymes and decreased the MDA content and inflammatory cytokines compared with those in the CFA group. Moreover, SJF could increase the mRNA expression of GPx-1 and CAT and inhibit the mRNA expression of IL-6 and TNF-α in the ankle tissue of CFA rats.

Pentahydroxy flavonoid isolated from Madhuca indica ameliorated adjuvant-induced arthritis via modulation of inflammatory pathways

Rheumatoid arthritis (RA) is an autoimmune disease associated with advanced joint dysfunction. Madhuca indica J. F. Gmel, from the family Sapotaceae, is an Indian medicinal plant reported to have an array of pharmacological properties. The aim of present investigation was to determine the anti-arthritic potential of an isolated phytoconstituent from methanolic leaf extract of Madhuca indica (MI-ALC) against FCA-induced experimental arthritis. Polyarthritis was induced in female rats (strain: Wistar) via an intradermal injection of FCA (0.1 mL) into the tail. Polyarthritis developed after 32 days of FCA administration. Then rats were treated orally with an isolated phytoconstituent from MI-ALC at doses of 5, 10, and 20 mg/kg. Findings suggested that High-Performance Thin-Layer Chromatography, Fourier-Transform Infrared Spectroscopy, and Liquid Chromatography-Mass Spectrometry spectral analyses of the phytoconstituent isolated from MI-ALC confirmed the structure as 3,5,7,3′,4′-Pentahydroxy flavone (i.e., QTN). Treatment with QTN (10 and 20 mg/kg) showed significant (p < 0.05) inhibition of increased joint diameter, paw volume, paw withdrawal threshold, and latency. The elevated synovial oxidative stress (Superoxide dismutase, reduced glutathione, and malondialdehyde) and protein levels of Tumor necrosis factor-α (TNF-α) and Interleukin (ILs) were markedly (p < 0.05) reduced by QTN. It also effectively (p < 0.05) ameliorated cyclooxygenase-2 (COX-2), Nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-kβ) and its inhibitor-α (Ikβα), and ATP-activated P2 purinergic receptors (P2X7) protein expressions as determined by western blot analysis. In conclusion, QTN ameliorates FCA-induced hyperalgesia through modulation of elevated inflammatory release (NF-kβ, Ikβα, P2X7, and COX-2), oxido-nitrosative stress, and pro-inflammatory cytokines (ILs and TNF-α) in experimental rats.

Quercetin decreases the antinociceptive effect of diclofenac in an arthritic gout-pain model in rats

OBJECTIVE

To analyse the antinociceptive interaction between quercetin (QUER) and diclofenac (DIC) in experimental arthritic gout-pain.

METHODS

The antinociceptive effect of DIC and QUER alone and in combination were evaluated using an arthritic gout-pain model. Pain was induced through intra-articular administration of uric acid in the rats and the treatments were administered 2 h later. Additionally, the cyclooxygenase (COX) activity was determined in rats treated with DIC, QUER and their combination.

KEY FINDINGS

DIC induced a maximal effect of 69.7 ± 2.7% with 3.1 mg/kg; whereas QUER only produced 17.6 ± 2.6% with the maximal dose (316 mg/kg). Ten of twelve DIC + QUER combinations showed a lesser antinociceptive effect than DIC alone did (P < 0.05). Moreover, DIC reduced total-COX (70.4 ± 1.3 versus 52.4 ± 1.8 and 77.4 ± 9.0 versus 56.1 ± 1.3, P < 0.05) and COX-2 (60.1 ± 1.0 versus 42.4 ± 1.8 and 58.1 ± 2.4 versus 48.7 ± 1.3, P < 0.05) activity after 1 and 3 h, respectively. Nevertheless, only the COX-2 activity induced by DIC was prevented in the presence of QUER (63.2 ± 3.0 versus 60.1 ± 1.0 and 56.6 ± 1.3 versus 58.1 ± 2.4 at 1 and 3 h, respectively).

CONCLUSIONS

All these data demonstrated that the simultaneous administration of QUER + DIC produces an unfavorable interaction on the antinociceptive effect of DIC. Therefore, this combination might not be recommendable to relieve arthritic gout-pain.

Flavonoid and cannabinoid impact on the ocular surface

PURPOSE OF REVIEW

To evaluate the impact of flavonoids and cannabinoids as anti-inflammatory and antiallergic treatments on the anterior surface of the eye.

RECENT FINDINGS

Allergic conjunctivitis and dry eye syndrome are common ocular surface diseases that have been treated with traditional pharmacological measures, e.g. corticosteroids, antihistamines. Given the side-effect profiles of these medications and the growing interest in complementary treatment modalities as part of integrative medical interventions, well known flavonoids, such as quercetin and catechin, are under investigation for topical and systemic application methods for relief. As flavonoid derivatives, pycnogenol and epigallocatechin gallate have alleviated dry eye symptoms, including lacrimal gland inflammation, tear secretion, and the stability of the tear film. Research on ocular cannabinoid receptors and response to synthetic cannabinoids are also being considered for therapy of anterior ocular disorders. The expansion of herbal formulations provides a framework for future treatment regimens for ocular surface disorders.

SUMMARY

Flavonoids and cannabinoids show promise as potential complementary treatment for allergic diseases because of their anti-inflammatory and antiallergic properties. Several studies implementing ocular and systemic application of these compounds show potential in becoming adjuvant treatment strategies for improving quality of life while also managing ocular surface disease processes.

Active rheumatoid arthritis in a mouse model is not an independent risk factor for periprosthetic joint infection

INTRODUCTION

Periprosthetic joint infection (PJI) represents a devastating complication of total joint arthroplasty associated with significant morbidity and mortality. Literature suggests a possible higher incidence of periprosthetic joint infection (PJI) in patients with rheumatoid arthritis (RA). There is, however, no consensus on this purported risk nor a well-defined mechanism. This study investigates how collagen-induced arthritis (CIA), a validated animal model of RA, impacts infectious burden in a well-established model of PJI.

METHODS

Control mice were compared against CIA mice. Whole blood samples were collected to quantify systemic IgG levels via ELISA. Ex vivo respiratory burst function was measured via dihydrorhodamine assay. Ex vivo Staphylococcus aureus Xen36 burden was measured directly via colony forming unit (CFU) counts and crystal violet assay to assess biofilm formation. In vivo, surgical placement of a titanium implant through the knee joint and inoculation with S. aureus Xen36 was performed. Bacterial burden was then quantified by longitudinal bioluminescent imaging.

RESULTS

Mice with CIA demonstrated significantly higher levels of systemic IgG compared with control mice (p = 0.003). Ex vivo, there was no significant difference in respiratory burst function (p = 0.89) or S. aureus bacterial burden as measured by CFU counts (p = 0.91) and crystal violet assay (p = 0.96). In vivo, no significant difference in bacterial bioluminescence between groups was found at all postoperative time points. CFU counts of both the implant and the peri-implant tissue were not significantly different between groups (p = 0.82 and 0.80, respectively).

CONCLUSION

This study demonstrated no significant difference in S. aureus infectious burden between mice with CIA and control mice. These results suggest that untreated, active RA may not represent a significant intrinsic risk factor for PJI, however further mechanistic translational and clinical studies are warranted.

Quercetin modified electrospun PHBV fibrous scaffold enhances cartilage regeneration

It suggests that the poly (3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) scaffold can be used for cartilage tissue engineering, but PHBV is short of bioactivity that is required for cartilage regeneration. To fabricate a bioactive cartilage tissue engineering scaffold that promotes cartilage regeneration, quercetin (QUE) modified PHBV (PHBV-g-QUE) fibrous scaffolds were prepared by a two-step surface modification method. The PHBV-g-QUE fibrous scaffold facilitates the growth of chondrocytes and maintains chondrocytic phenotype resulting from the upregulation of SOX9, COL II, and ACAN. The PHBV-g-QUE fibrous scaffold inhibited apoptosis of chondrocyte and reduced oxidative stress of chondrocytes by regulating the transcription of related genes. Following PHBV-g-QUE fibrous scaffolds and PHBV fibrous scaffolds with adhered chondrocytes were implanted into nude mice for 4 weeks, it demonstrated that PHBV-g-QUE fibrous scaffolds significantly promoted cartilage regeneration compared with the PHBV fibrous scaffolds. Hence, it suggests that the PHBV-g-QUE fibrous scaffold can be potentially applied in the clinical treatment of cartilage defects in the future.